The invention generally relates to an ankle joint prosthesis that can be positioned for walking, and effectively transitioned to multiple orientations as for use while engaging adaptive sports activities, and in regards to this invention; aquatic and equestrian activity.
The following patents may be relevant to the present invention:
U.S. PATENT DOCUMENTS    U.S. Pat. No. 911,243 February 1909 Johannesen    U.S. Pat. No. 2,749,557 June 1956 Riddle    U.S. Pat. No. 3,419,227 December 1968 Werkmeister et al.    U.S. Pat. No. 3,480,972 December 1969 Prahl    U.S. Pat. No. 4,413,360 November 1983 Lamb et al.    U.S. Pat. No. 4,865,611 September 1989 Al-Turaiki    U.S. Pat. No. 5,156,630 October 1992 Rappoport et al.
FOREIGN PATENT DOCUMENTS    0262319 January 1970 Russian Federation    2110806 October 1971 Federal Republic of Germany    0381347 May 1973 Russian Federation    1509641 May 1978 United Kingdom    0016268 October 1980 European Patent Office
The most relevant patent to the present invention may be U.S. Pat. No. 5,156,630; Inventors: A. Rappoport, S. Shawe, and M. Ross; Issue Date 20 Oct. 1992. U.S. Pat. No. 5,156,630 to Rappoport, Shawe, & Ross is directed to an ankle joint prosthesis comprised of an upper part for attachment to an artificial leg and a lower part for attachment to an artificial foot, with the upper and lower parts rotatively coupled and capable of being fixed in a first position for walking, a second fixed position for swimming, or a free-flexing mode for rowing, and skiing.
Changing positions is effected by manually rotating a D-ring on the medial side of the ankle prosthesis by hand.
Materials of construction of the ankle body is precision machined from lightweight/high strength plastic.
Although the ankle joint prosthesis discussed above can be adjusted manually, it suffers some notable deficiencies, specifically; method of manipulation, limited fixed positions, and strength of materials utilized.
Manually rotating the ankle by hand requires the prosthesis wearer to be stationary by means of standing on one leg or sitting to be able to fix the ankle into and out of the locked positions; this is not a desirable transition mode if you desire to be dynamic into and out of the water, either at a beach, pool or climbing a boat ladder.
The fixed and locked positions are set for walking, and at approximately 75 degrees plantar flexion orientation for swim position only. The free-flex mode is used when the ankle joint is required to rotation freely, i.e. no resistance or ability to fix position.
The ankle embodiment is made from lightweight/high strength plastic, but may not be durable during high energy activity.